The workservers would hang or crash when using Microsoft Word to convert the FCS. You couldn't stop them in the Enterprise Fax Manager; they would just stay in a "stopping" state. You would have to kill the workserver.exe processes. Converting these to the RightFax native PCL format solved the issue and increased the stability and performance of RightFax in a huge way.
FCS (Fax Cover Sheets) are stored in Rightfax\FCS. The source (word document) file is in a subfolder of FCS. Typically the cover sheet should be PCL format. See the AdministratorsGuide.pdf for details on how to create a FCS.
Using the built-in Windows 2000 HP LaserJet 4000 PCL driver produced the best results for us.
Here are some articles from Captaris that are useful:
190 - How do I run a RightFax 8.x or 9.0 WorkServer in Debug Mode?
3537 - Important information on Server Side Application (SSA) conversion using Microsoft Office applications
Basically don't use Word to do your fax cover sheet (FCS) conversion…..